【正确答案】There are two key differences between distance education and traditional education. Distance education adds flexibility and openness, irrespective of time, place, or pace of learning. Here an instructor teaches, and somewhere else a student learns, breaking barriers of place. Instruction may take place in real time or on a time-delayed basis. Distance education modes are as varied and numerous as the courses themselves. Generally speaking, there are three basic transmission modes in distance education: live TV broadcast, transmission of complete or compressed information, and computer-based instruction. Of course, all these modes can also be used in combination. For instance, live broadcasts via satellite or the World Wide Web can be added in courses conducted primarily with videotapes.